Yet again, the world watches as the spectre of famine haunts the Horn of Africa and surrounding region.

"We are facing a tragedy," says Antonio Guterres, the UN secretary general. "We must avoid it becoming a catastrophe."

Drought is widespread across the region and temperatures have been rising. Crops have failed, people are going hungry and hundreds of thousands of livestock have died.

We are facing a tragedy. We must avoid it becoming a catastrophe

- Antonio Guterres, UN chief

According to latest estimates, 16 million people in East Africa are facing starvation: across the Gulf of Aden in Yemen, the UN has launched an appeal aimed at providing what it calls life-saving assistance to another 12 million.

"Without international support, they [the Yemenis] may face the threat of famine in the course of 2017 and I urge donors to sustain and increase their support to our collective response," says Stephen O'Brien, the UN's under-secretary-general for humanitarian affairs.

Violence and conflict – particularly in Yemen, South Sudan and Somalia – are major factors behind the crisis, with supplies of food disrupted and already poor infrastructure destroyed or severely damaged.

Add climate change

Interwoven with conflict are changes in climate, adding to the suffering of some of the world's most impoverished people.

Mainly as a result of the increased amount of carbon dioxide and other so-called greenhouse gases we are pumping into the atmosphere, the world is becoming warmer, with global average temperatures rising by 0.99 since 1880.

The average temperature in Yemen has increased by 1.8C since 1960 – a rate double the global average

That might not sound like very much, but in the distant past, temperature changes of between one and two degrees were enough to bring about enormous change, flooding continents when it became hotter or plunging the earth into an ice age when temperatures dropped.

Also, the global average hides local, more pronounced, changes in temperature, with the Middle East and North Africa region heating up at a rate faster than most other areas on the planet.

For example, the average temperature in Yemen has increased by 1.8C since 1960 – a rate double the global average. With warming, weather systems become more erratic and energetic.

Though drought has been a feature of life across East Africa and in Yemen for many years, aid agencies say dry periods are becoming ever more frequent with severe water shortages in 2005, 2006, 2008, 2011, 2015, 2016 and now 2017.

The droughts have also been becoming more severe; more than a quarter of a million people – half of them children under five - died in Somalia in 2011 in what the UN described as the worst drought to hit the region in 60 years.

This year, the situation could be even more dire with food stocks already depleted by successive years of chronic water shortages.

A protester holds a placard during a protest outside the US embassy in Tokyo (AFP)

Poor predictions

The long-term outlook is not good. In the past, climate scientists suggested that, although temperatures would rise in the region, this would be compensated by increased rainfall.

A recent study, based on sediment cores going back thousands of years extracted from the Gulf of Aden, contradicts this view.

The study indicates that, in periods of the Earth's history when warm conditions prevailed, the Horn of Africa region was dryer – and wetter when it was colder.

"Right now, aid groups are expecting a wetter, greener future for the Horn of Africa, but our findings show that the exact opposite is occurring," says Peter deMenocal, one of the study's authors and head of the Centre for Climate and Life at Columbia University's Lamont-Doherty Earth Observatory.

The region is drying, and will continue to do so with rising carbon emissions

- Peter deMenocal, climate expert

"The region is drying, and will continue to do so with rising carbon emissions," says deMenocal.

The droughts of the past two years have been compounded by events far away in the Pacific where – in an event known as El Nino - the ocean waters have been at record levels of warmth.

The El Nino and associated systems influence the weather far away, causing torrential downpours in southern India – and acute drought in the Horn of Africa and surrounding region.

Adapting to changes in climate and increased levels of drought is difficult for many in the region. In the past, people would often lead a nomadic life, herding their animals over long distances to escape drought.

Changes already in the works

These traditional routes are now frequently blocked by border checkpoints or fences around privately held land. Cash crops, such as qat in Yemen, have drained already stressed water resources.

A proliferation of arms in the region often leads to serious violence breaking out over water.

Population growth is yet another factor. In Yemen, the population has expanded by more than 25 percent in the past 10 years, with 50 percent under the age of 18.

The Horn of Africa region and the entire Middle East and North Africa are feeling the impact of a warming world.

"These changes are likely to intensify existing water scarcity and aridity, bringing higher temperatures, more heat waves, lower and less reliable precipitation and more extreme rainfall events."

- Kieran Cooke is a former foreign correspondent for the BBC and the Financial Times, and continues to contribute to the BBC and a wide range of international newspapers and radio networks.

The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Middle East Eye.

Photo: Women carry firewood in March 2017 as they walk back to a makeshift camp on the outskirts of Baidoa, in the southwestern Bay region of Somalia, where thousands of internally displaced people arrive daily after fleeing the parched countryside (AFP)